Abstract
A 6-month-old girl presented with hypotonia and mild psychomotor retardation. Subsequently, an atypical manifestation of a nonketotic hyperglycinaemia was diagnosed, confirmed by significantly reduced activity of the glycine cleavage system in the liver tissue. After the patient developed hypsarrhythmia and had a single cerebral seizure, treatment with both sodium benzoate and dextromethorphan was started. During the following year, the girl was free of seizures with improvement of the EEG activity and showed retarded but continuously progressing psychomotor development. At the age of 20 months she began to walk freely but had generalized muscular hypotonia and moderate mental retardation. Discontinuation of dextromethorphan medication after one year of treatment did not change the clinical and electroencephalographic status. However, after cessation of sodium benzoate therapy, epileptic activity in the EEG and behavioural changes occurred. These changes disappeared promptly after sodium benzoate therapy was reinstituted. Thus, this case of mild atypical nonketotic hyperglycinaemia with only moderate psychomotor retardation and without epilepsy benefited from treatment with sodium benzoate in terms of electroencephalographic and behavioural changes.
Similar content being viewed by others
REFERENCES
Alemzadeh R, Gammeltoft K, Matteson K (1996) Efficacy of low-dose dextromethorphan in the treatment of nonketotic hyperglycinemia. Pediatrics 97: 924-926.
Barshop BA, Breuer J, Holm J, Leslie J, Nyhan WL (1989) Excretion of hippuric acid during sodium benzoate therapy in patients with hyperglycinemia or hyperammonaemia. J Inher Metab Dis 12: 72-79.
Benveniste M, Mayer ML (1991) Kinetic analysis of antagonist action at Ν-methyl-Ũ-aspartatic acid receptors. Two bindings sites each for glutamate and glycine. Biophys J 59: 560-573.
Boneh A, Degani Y, Harari M (1996) Prognostic clues and outcome of early treatment of nonketotic hyperglycinemia. Pediatr Neurol 15: 137-141.
Christodoulou J, Kure S, Hayasaka K, Clarke JT (1993) Atypical nonketotic hyperglycinemia confrmed by assay of the glycine cleavage system in lymphoblasts. J Pediatr 123: 100-102.
Flannery DB, Pellock J, Bousounis D, Hunt P, Nance C, Wolf B (1983) Nonketotic hyperglycinemia in two retarded adults: a mild form of infantile nonketotic hyperglycinaemia. Neurology 33: 1064-1066.
Frazier DM, Summer GK, Chamberlin HR (1978) Hyperglycinuria and hyperglycinemia in two siblings with mild developmental delay. Am J Dis Child 132: 777-781.
Hamosh A, McDonald JW, Valle D, Francomano CA (1990) Combination benzoate and dextromethorphan therapy for nonketotic hyperglycinemia. Am J Hum Genet 47: A157.
Hamosh A, McDonald JW, Valle D, Francomano CA, Niedermeyer E, Johnston MV (1992) Dextromethorphan and high-dose benzoate therapy for nonketotic hyperglycinemia in an infant. J Pediatr 121: 131-135.
Hamosh A, Johnston MV, Valle D (1995) Nonketotic hyperglycinemia. In Scriver CR, Beaudet AL, Sly WS, Valle D, eds. The Metabolic and Molecular Bases of Inherited Disease, 7th edn. New York: McGraw-Hill, 1337-1348.
Hamosh A, Maher JF, Bellus GA, Rasmussen SA, Johnston MV (1998) Long-term use of high-dose benzoate and dextromethorphan for the treatment of nonketotic hyperglycinemia. J Pediatr 132: 709-713.
Hayasaka K, Tada K, Fueki N, et al (1987) Nonketotic hyperglycinemia: analyses of glycine cleavage system in typical and atypical cases. J Pediatr 110: 873-877.
Holmgren G, Blomquist HK (1997) Nonketotic hyperglycinemia in two sibs with mild psycho-neurological symptoms. Neuropaediatrie 8: 67-69.
Schmitt B, Steinmann B, Gitzelmann R, Thun-Hohenstein L, Mascher H, Dumermuth G (1993) Nonketotic hyperglycinemia: clinical and electrophysiologic e.ects of dextromethorphan, an antagonist of the NMDA receptor. Neurology 43: 421-424.
Singer HS, Valle D, Hayasaka K, Tada K (1989) Nonketotic hyperglycinemia: studies in an atypical variant. Neurology 39: 286-288.
Wol. JA, Kulovich S, Yu-Al, Qiao CN, Nyhan WL (1986) The effectiveness of benzoate in the management of seizures in nonketotic hyperglycinemia. Am J Dis Child 140: 596-602.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Neuberger, J.M., Schweitzer, S., Rolland, MO. et al. Effect of sodium benzoate in the treatment of atypical nonketotic hyperglycinaemia. J Inherit Metab Dis 23, 22–26 (2000). https://doi.org/10.1023/A:1005642728513
Issue Date:
DOI: https://doi.org/10.1023/A:1005642728513